1. Field of the Invention
This invention relates to the field of aminoplast resins. More particularly, this invention concerns a new highly stable urea-formaldehyde type composition for the treatment of cellulose-containing materials.
2. Description of the Prior Art
The manufacture of urea-formaldehyde condensates in general is an old and well established art as is their use for various purposes including textile finishing. Thus, for example, dimethylol urea is a well known textile finishing agent for imparting durable wrinkle recovery and shrinkage control to textile materials containing or being derived from cellulose. Additionally, other types of amino-plast resins such as methylolated carbamates are well known as creaseproofing chemicals (see U.S. Pat. No. 3,524,876 and U.S. Pat. No. 3,369,858).
One of the major problems encountered with urea-formaldehyde precondensates of the water soluble type has been the lack of stability of such condensates particularly in highly concentrated form. Consequently, in marketing such condensates, it has been necessary to ship from the original place of preparation a relatively dilute solution, generally in concentrations in the range from 10 to 15%. Thus, the cost of transportation per unit of active material is relatively high inasmuch because of the high water content. At the point of use, if a more concentrated solution is desired, this water must then be removed which adds to the total process cost.
Additionally, an inherent problem in the materials known heretofore has been the presence of a relatively high urea to formaldehyde ratio. This cause disadvantages in that at high ratios, free formaldehyde is released into the atmosphere which, besides being disagreeable, constitutes a health hazard.